1. Field of the Invention
The present invention relates generally to transfer apparatus for transferring an article laterally off of a conveyor system.
2. Description of the Prior Art
In the design of conveyor systems such as those utilized in manufacturing operations and warehousing and shipping operations, roller type conveyors are often utilized.
A roller conveyor has a plurality of regularly spaced cylindrical rollers upon which the articles, typically boxes, roll as the articles move along the length of the conveyor.
The rollers are powered in order to drive the articles along the conveyor, and power can be provided to the rollers in many different ways.
One conventional type of driven roller conveyor system is that generally known as a belt driven live roller system. A belt driven live roller system utilizes an endless drive belt that runs along the center of the conveyor with the upper side of the drive belt engaging lower surfaces of the drive rollers so that the drive rollers are driven by the drive belt. A series of idler rollers are located on the opposite side of the drive belt from the drive rollers in order to create the appropriate frictional engagement of the drive belt with the drive rollers.
Another conventional type of driven roller conveyor system is that known as a line shaft drive conveyor. A line shaft drive conveyor has a drive shaft located below the rollers and typically oriented adjacent the edge of one side of the conveyor. Each of the drive rollers is connected to the drive shaft by a flexible belt oriented in somewhat of a figure-8 shape so as to transfer the rotation of the drive shaft to rotation of the drive rollers.
Other types of driven roller conveyor systems include a xe2x80x9cDC rollerxe2x80x9d system wherein some of the rollers have electric motors built into them, and each motor driven roller is connected to several other non-powered rollers with flexible drive belts. One DC powered roller will drive four or five adjacent rollers.
With any conveyor system there is a need for a transfer apparatus to move selected articles laterally off of the main conveyor.
With some of the above noted standard forms of driven roller conveyors, such as for example, the line shaft drive conveyor, transfer mechanisms have been constructed which utilize a plurality of transfer drive belts carried on a transfer frame. When it is desired to move an article laterally off of the conveyor, the transfer frame raises up so that the transfer drive belts extend up above the top of the rollers to lift an article off of the rollers. The drive belts are oriented parallel to the rollers and thus, the drive belts will move the article laterally when it engages the article.
With other types of driven roller conveyor systems, however, such as for example, the belt driven live roller conveyor, such a transfer mechanism has never been possible because the main conveyor drive belt is located along the center line of the conveyor and thus would interfere with the placement of such a transfer device. Accordingly, the transfer devices used to date with belt driven live roller systems have consisted of a pusher mechanism located at an elevation above the main conveyor rollers, which simply engages the article and shoves it laterally off of the main conveyor. As will be appreciated by those skilled in the art, such a pusher type transfer device does not provide precise control of the articles which are being moved laterally.
Accordingly, there is a continuing need for improved transfer devices, and particularly for improved transfer devices for use with a belt driven live roller conveyor system.
In a first embodiment the present invention provides a transfer device for transferring articles laterally off of a conveyor such as a belt driven live roller conveyor. The apparatus includes at least one, and preferably a plurality of transfer drive belts. Each of the drive belts is mounted upon a transfer frame with a plurality of belt guides, preferably roller pulleys. Each drive belt is mounted upon its respective belt guides so as to define a serpentine belt path having first and second uppermost belt portions for engaging the article to be transferred, and a lower belt portion located between the first and second uppermost belt portions. This provides a U-shape path for the upper portion of the transfer drive belt, with the bottom of the U being sufficiently deep that a conventional main conveyor drive belt of a belt driven live conveyor system can be received within the U. Thus the first and second uppermost belt portions will rise up through the rollers of the conveyor system on either side of the main conveyor drive belt to engage the article and move it laterally off of the main conveyor. A lifting mechanism is operably associated with the transfer frame and moved between a retracted position wherein the drive belt is located below the articles on the conveyor, and a raised position wherein the first and second uppermost belt portions of each transfer drive belt engage the article to be transferred.
Preferably the transfer drive belt is a toothed belt and it is driven from a toothed drive sprocket driven by a drive motor. The motor preferably has a brake so that very precise position control can be provided to the article being transferred.
The lifting mechanism preferably includes an actuating ram having an axis oriented parallel to the rollers and thus parallel to the width of the main conveyor system.
The apparatus preferably includes a stop abutment attached to the transfer frame and extending upwardly on an upstream side of the transfer apparatus so that when the lifting mechanism is in its raised position, the stop abutment extends above the main roller conveyor.
Certain aspects of the invention such as the toothed drive belts with associated toothed sprocket and motor with a motor brake, the lifting mechanism having the actuating ram oriented parallel to the width of the main conveyor, and the use of the stop abutment are also applicable to other types of conveyor systems other than the belt driven live roller conveyor system. For example, these features may be utilized with a line shaft drive conveyor system.
Accordingly, it is an object of the present invention to provide an improved transfer mechanism for use with conveyor systems.
Another object of the present invention is the provision of a transfer mechanism which may be utilized with a belt driven live roller conveyor system.
And another object of the present invention is the provision of a transfer mechanism utilizing toothed belts, particularly with a toothed drive sprocket driven by a motor having a motor brake so as to provide precise lateral position control.
And another object of the present invention is the provision of transfer mechanisms utilizing a stop abutment to prevent interference by a following article with an article being laterally transferred.
And another object of the present invention is the provision of an improved lifting mechanism for use with a transfer apparatus.
And another object of the present invention is the provision of a transfer mechanism which can easily be removed from the main conveyor system by simply unbolting a support frame from the frame of the main conveyor system and dropping the transfer mechanism out from between the rollers of the main conveyor system.
Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the following disclosure when taken in conjunction with the accompanying drawings.